1. Field of the Invention
This invention relates to a heat dissipating device, more particularly to a heat dissipating device which can ensure circulation of a working fluid to thereby increase the efficiency of the heat dissipating device.
2. Description of the Related Art
Referring to FIG. 1, a conventional heat dissipating device 10 for use in computer systems is shown to include a cooling device 11 which is adapted to be mounted on a heat generating component, a heat dissipating fan 12, and a heat dissipating fin 13. The cooling device 11 contains a working fluid and has a delivery pipe 111 for delivering the working fluid to the fin 13. The heat dissipating fan 12 has a top side formed with an air inlet 121, and a lateral side formed with an air outlet 122. The fin 13 is disposed adjacent to the air outlet 122 and is formed with a channel 131 for extension of the delivery pipe 111. Therefore, when the working fluid in the cooling device 11 absorbs heat from the heat generating component, the working fluid is cooled by simply delivering the working fluid through the delivery pipe 11 which is connected to the heat dissipating fin 13. At the same time, the heat dissipating fan 12 continuously blows air through the air outlet 122 to the heat dissipating fin 13 in order to assist in the cooling of the working fluid. However, the conventional heat dissipating device 10 has several drawbacks. First of all, since the cooling device 11 is not associated with any circulation device, the movement of the working fluid is very slow. As such, the temperature reduction of the working fluid is limited to where the delivery pipe 111 is in contact with the heat dissipating fin 13. Therefore, it is usually quite difficult to reduce the temperature to the desired range which dramatically decreases the efficiency of the heat dissipating device 10. Secondly, since only a small section of the delivery pipe 111 is in contact with the heat dissipating fin 13, the effect of heat exchanging can only occur around the peripheral surfaces of the section of the delivery pipe 111 which is in contact with the heat dissipating fin 13. Since the contacting surface is rather small, the heat dissipation is obviously not effective.
Therefore, the object of the present invention is to provide a heat dissipating device which allows the working fluid to circulate and which prolongs the time for heat exchanging and increases the surface area for heat dissipation so as to increase the efficiency of the heat dissipating device.
According to this invention, a heat dissipating device comprises a heat dissipating fin unit made of a heat-conductive material, and a heat dissipating fan unit mounted on the fin unit and operable so as to generate cooling air for cooling the fin unit. The heat dissipating device further comprises a heat exchanger including a hollow contact body that is made of a heat-conductive material, that is disposed adjacent to the fin unit, and that contains an amount of working fluid therein. The contact body is adapted to be disposed in contact with a heat generating component. The heat exchanger further includes a delivery pipe that is connected to the contact body to permit exit of the working fluid from the contact body, and a supply pipe that is connected to the contact body to permit entry of the working fluid into the contact body. The supply pipe is mounted to the heat dissipating fin unit to permit cooling of the working fluid in the supply pipe. A pump is connected to the delivery pipe and the supply pipe, and is operable so as to draw the working fluid from the contact body via the delivery pipe and to supply the working fluid into the contact body via the supply pipe. The working fluid is cooled by the fin unit while passing through the supply pipe.